Smoky Quartz Soaprock

Information about the Smoky Quartz Soaprock:

Handmade in the U.S.A. and each soaprock is a unique work of art.

Size: Full Bath Size - about 5" x 4" x 2.5"
Approximate Weight: 6oz.
Fragrance: Midnight Moon


Some facts about Smoky Quartz:

Smoky quartz is the state gem of New Hampshire. The color of smoky quartz is caused by radiation and traces of aluminum built into its crystal lattice. Aluminum replaces silicon creating an imbalance of charge in the lattice, small monovalent cations (H+, Li+ or Na+) are built into the lattice, as well. High energy radiation transfers the extra electron, and a color center is formed. Interestingly, H+ seems to interfere with this process, and higher concentrations of built-in hydrogen inhibit the formation of color-centers. In normal geological environments this process can only take place at temperatures below 50°C, otherwise the rate of color center destruction surpasses that of color center formation. So the color of the crystals appeared long after the crystals have grown. It is estimated that it takes several million years for a crystal to assume a deep color in a granite of average composition.

Sometimes it is said that it is the high energy cosmic radiation that causes the coloration and not the radiation from radioactive sources. At least for alpine quartz, although this is very unlikely. There are reports about alpine vugs in which both smoky quartz and rock crystals have been found. Calcite grew on some of the crystals and shielded them from the radiation coming from the surrounding rocks. Cosmic radiation that penetrated the entire mountain would definitely not be stopped by a layer of calcite. In addition, quartz from Arkansas, for example, is laying in the ground for quite some time (about 200 million years) and should already be at least a little smoky. Although it can easily be turned into smoky quartz by artificial irradiation, the quartz found there is colorless.

The color of smoky quartz is typically much more homogeneous than that of amethyst, but often still more intense at the tips of the crystals. Crystals that show a zonar or patchy coloration are not uncommon, however, and often these are most intensely colored at the edges between the rhombohedral faces. Sometimes a dark color is caused by impurities like organic compounds or manganese oxide, but those rocks should not be called "smoky quartz". That name is reserved for quartz whose color has been induced by radiation.

True smoky quartz will loose its color when heated to about 200°C, and the color will occur again when the crystal is irradiated with x- or gamma-rays. Some smoky quartz is sensitive to ultraviolet light and will pale when exposed to sunlight for a long time. Although it is not as sensitive as amethyst.